This invention relates generally to marking instruments capable of counting the number of marking strokes and more particularly to ball point, felt tip and other writing instruments in which the tip of the instrument is presses against an object to mark the object as well as to perform a counting operation.
Such apparatus has particular application, for example, to the counting of the holes in a target created by the pellets from a shot gun and it is particularly desirable to not only mark the holes that have already been counted as well as to perform a count. Other applications for such appartus include lumber yards where it is desirable to make a tally of shipments. Similarly, such apparatus also has applications in warehouses and stock rooms where it is desirable to count pallets, cartons, skids racks, boxes, tubes or other tangable goods.
The prior art includes apparatus of this general type such as that shown in U.S. Pat. No. 4,726,044. A problem with utilizing such apparatus is that the apparatus does not provide a way to differentiate the marks that are made, for example, at the end of one acconting period instead of a second counting period. For example, a blue check mark indicates that a given rack, box, tube, pallet or skid has been counted and the same symbol and color is used in a succeeding counting period then it would be difficult to establish whether a given item has been accounted for. The apparatus as shown in U.S. Pat. No. 4,726,044 does not permit easy change of the pen instrument used in a counting process.
It is an object of the invention to provide apparatus that is a combination marker and counter and which allows easy differentiation between marks made at different times.
More particularly it is an object of the invention to provide apparatus tht allows easy change of the pen instrument so that colors which are placed on the article being counted have a distinctive nature.